@misc{tang2006lagrangian,
  title={Lagrangian dynamic formulation of a four-bar mechanism with minimal coordinates},
  author={Tang, Chin Pei},
  year={2006},
  publisher={Internal Report, March}
}

@book{Cindy,
author = {Jürgen, Richter-Gebert and Kortenkamp, Ulrich},
year = {1999},
month = {01},
pages = {},
title = {The Interactive Geometry Software Cinderella},
volume = {107},
booktitle = {The American Mathematical Monthly}
}

@misc{wiki:fourBar,
    author = "{Wikipedia contributors}",
    title = "Four-bar linkage --- {Wikipedia}{,} The Free Encyclopedia",
    year = "2018",
    url = "https://en.wikipedia.org/w/index.php?title=Four-bar_linkage&oldid=836129208",
    note = "[Online; accessed 15-April-2018]"
  }
